Department of Endocrinology, The Second Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510120, China.
Endocrine. 2011 Jun;39(3):242-50. doi: 10.1007/s12020-010-9428-z. Epub 2011 Apr 12.
The renin-angiotensin system (RAS) is reportedly involved in chronic diabetic complications such as diabetic nephropathy, but changes of the RAS in diabetic skin remain unknown. The aim of this study was to investigate the expression of angiotensin (Ang) II and its type 1 (AT1) and type 2 (AT2) receptors in diabetic skin tissues, and explore the relationship between the local RAS and pathological changes of diabetic skin. Our results showed that thinning of epidermis, degeneration of collagen, fracture of dermal layer, and atrophy/disappearance of subcutaneous fat were observed in diabetic skin. The expression level of AngII was increased in diabetic skin tissues compared to that in controls. mRNA and protein expression of AT1 receptor were also increased while the level of AT2 receptor decreased; the relative expression of AT1 to AT2 receptors was approximately threefold higher in diabetes than in controls. Furthermore, in the culture medium of primary cultured fibroblasts from diabetic skin, the concentration of AngII was significantly higher than that of normal control. The mRNA and protein expression of AT1 receptor was also increased in fibroblasts of diabetic skin compared to controls, while the protein expression of AT2 receptor was decreased. Taken together, our results suggest that the local RAS system is activated in diabetic skin and AngII receptor is likely to mediate the pathological changes of diabetic skin.
肾素-血管紧张素系统（RAS）据称参与慢性糖尿病并发症，如糖尿病肾病，但糖尿病皮肤中 RAS 的变化尚不清楚。本研究旨在研究血管紧张素（Ang）II 及其 1 型（AT1）和 2 型（AT2）受体在糖尿病皮肤组织中的表达，探讨局部 RAS 与糖尿病皮肤病理变化的关系。我们的结果表明，糖尿病皮肤存在表皮变薄、胶原变性、真皮层断裂、皮下脂肪萎缩/消失等病变。与对照组相比，糖尿病皮肤组织中 AngII 的表达水平升高。AT1 受体的 mRNA 和蛋白表达也增加，而 AT2 受体的水平降低；糖尿病患者中 AT1 受体与 AT2 受体的相对表达水平比对照组高约三倍。此外，在来自糖尿病皮肤的原代成纤维细胞的培养物中，AngII 的浓度明显高于正常对照组。与对照组相比，糖尿病皮肤成纤维细胞中 AT1 受体的 mRNA 和蛋白表达也增加，而 AT2 受体的蛋白表达减少。综上所述，我们的结果表明，局部 RAS 系统在糖尿病皮肤中被激活，AngII 受体可能介导糖尿病皮肤的病理变化。
